Transmitting apparatus and receiving apparatus and controlling method thereof

ABSTRACT

A transmitting apparatus is provided. The transmitting apparatus includes: a frame generator configured to generate a frame including a plurality of orthogonal frequency-division multiplexing (OFDM) symbols; and a guard interval (GI) inserter configured to insert GIs into the generated frame, wherein the plurality of OFDM symbols are divided into a bootstrap, a preamble, and a payload, and the GI inserter inserts first GIs having a size corresponding to a fast Fourier transform (FFT) size of each of OFDM symbols configuring the payload into front ends of each of the OFDM symbols, inserts second GIs having a size corresponding to a quotient obtained by dividing an extra region of the payload calculated based on the FFT size of the OFDM symbols configuring the payload, the number of OFDM symbols, and the size of the first GIs by the number of OFDM symbols into front ends of each of the first GIs, and inserts a cyclic postfix (CP) having a size corresponding to the remainder remaining after dividing the extra region of the payload by the number of OFDM symbols into a rear end of a final OFDM symbol configuring the payload.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.62/115,846, filed on Feb. 13, 2015, and Korean Patent Application No.10-2016-0014351, filed on Feb. 4, 2016, in the Korean IntellectualProperty Office, respectively, the disclosures of which are incorporatedherein in their entirety by reference.

BACKGROUND

1. Field

Apparatuses and methods consistent with the exemplary embodiments relateto a transmitting apparatus, a receiving apparatus, and a signalingmethod thereof, which transmit data by mapping the data to at least onesignal processing path.

2. Description of the Related Art

In the information-oriented society of the 21st century, broadcastingcommunication services are entering an era of digitization,multi-channel, broadband, and high quality. In particular, ashigh-quality digital television (TV), portable multimedia players (PMP),and portable broadcasting apparatuses have been increasingly used inrecent years, even in digital broadcasting services, a demand forsupporting various receiving methods has been increased.

In an actual state in which the standard group has established variousstandards according to demands to provide various services to satisfyuser's needs, it is required to find methods for providing betterservices having improved performance.

SUMMARY

The present disclosure provides a transmitting apparatus distributingand disposing an extra region of a payload, a receiving apparatus, and acontrolling method thereof.

According to an aspect of the present disclosure, a transmittingapparatus includes: a frame generator configured to generate a frameincluding a plurality of orthogonal frequency-division multiplexing(OFDM) symbols; and a guard interval (GI) inserter configured to insertGIs into the generated frame, wherein the plurality of OFDM symbols aredivided into a bootstrap, a preamble, and a payload, and the GI inserterinserts first GIs having a size corresponding to a fast Fouriertransform (FFT) size of each of OFDM symbols configuring the payloadinto front ends of each of the OFDM symbols, inserts second GIs having asize corresponding to a quotient obtained by dividing an extra region ofthe payload calculated based on the FFT size of the OFDM symbolsconfiguring the payload, the number of OFDM symbols, and the size of thefirst GIs by the number of OFDM symbols into front ends of each of thefirst GIs, and inserts a cyclic postfix (CP) having a size correspondingto the remainder remaining after dividing the extra region of thepayload by the number of OFDM symbols into a rear end of a final OFDMsymbol configuring the payload.

The CP may include portions of the final OFDM symbol configuring thepayload.

The first and second GIs may include portions of each of the OFDMsymbols.

The CP may include samples from a start point of the final OFDM symbolto a point corresponding to a size of the remainder, among a pluralityof samples configuring the final OFDM symbol.

The first and second GIs may include samples from a final point of theOFDM symbol to a point corresponding to the sum of a size correspondingto the FFT size of the OFDM symbol and a size of the quotient, among aplurality of samples configuring the OFDM symbol.

The GI inserter may generate information on whether the extra region ofthe payload is distributed and a disposition reference of the extraregion.

The transmitting apparatus may further include a transmitter configuredto transmit the frame including the generated information.

According to another aspect of the present disclosure, a receivingapparatus includes: a receiver configured to receive a stream includinga frame including a bootstrap, a preamble, and a payload; a bootstrapdetector configured to detect the bootstrap in the frame; and a signalprocessor configured to signal-process the preamble based on thedetected bootstrap and signal-process the payload based on thesignal-processed preamble, wherein first GIs having a size correspondingto an FFT size of each of OFDM symbols configuring the payload areinserted into front ends of each of the OFDM symbols, second GIs havinga size corresponding to a quotient obtained by dividing an extra regionof the payload calculated based on the FFT size of the OFDM symbolsconfiguring the payload, the number of OFDM symbols, and the size of thefirst GIs by the number of OFDM symbols are inserted into front ends ofeach of the first GIs, and a cyclic postfix (CP) having a sizecorresponding to the remainder remaining after dividing the extra regionof the payload by the number of OFDM symbols is inserted into a rear endof a final OFDM symbol configuring the payload.

The signal processor may signal-process the payload based on informationon whether the extra region of the payload is distributed and adisposition reference of the extra region, included in the bootstrap andthe preamble.

The signal processor may perform channel estimation based on the CPinserted into the rear end of the final OFDM symbol.

According to still another aspect of the present disclosure, acontrolling method of a transmitting apparatus includes: generating aframe including a plurality of OFDM symbols; and inserting GIs into thegenerated frame, wherein the plurality of OFDM symbols are divided intoa bootstrap, a preamble, and a payload, and in the inserting, first GIshaving a size corresponding to an FFT size of each of OFDM symbolsconfiguring the payload are inserted into front ends of each of the OFDMsymbols, second GIs having a size corresponding to a quotient obtainedby dividing an extra region of the payload calculated based on the FFTsize of the OFDM symbols configuring the payload, the number of OFDMsymbols, and the size of the first GIs by the number of OFDM symbols areinserted into front ends of each of the first GIs, and a cyclic postfix(CP) having a size corresponding to the remainder remaining afterdividing the extra region of the payload by the number of OFDM symbolsis inserted into a rear end of a final OFDM symbol configuring thepayload.

The CP may include portions of the final OFDM symbol configuring thepayload.

The first and second GIs may include portions of each of the OFDMsymbols.

The CP may include samples from a start point of the final OFDM symbolto a point corresponding to a size of the remainder, among a pluralityof samples configuring the final OFDM symbol.

The first and second GIs may include samples from a final point of theOFDM symbol to a point corresponding to the sum of a size correspondingto the FFT size of the OFDM symbol and a size of the quotient, among aplurality of samples configuring the OFDM symbol.

In the inserting, information on whether the extra region of the payloadis distributed and a disposition reference of the extra region may begenerated.

The controlling method of a transmitting apparatus may further includetransmitting the frame including the generated information.

According to yet still another aspect of the present disclosure, acontrolling method of a receiving apparatus includes: receiving a streamincluding a frame including a bootstrap, a preamble, and a payload;detecting the bootstrap in the frame; and signal-processing the preamblebased on the detected bootstrap and signal-processing the payload basedon the signal-processed preamble, wherein first GIs having a sizecorresponding to an FFT size of each of OFDM symbols configuring thepayload are inserted into front ends of each of the OFDM symbols, secondGIs having a size corresponding to a quotient obtained by dividing anextra region of the payload calculated based on the FFT size of the OFDMsymbols configuring the payload, the number of OFDM symbols, and thesize of the first GIs by the number of OFDM symbols are inserted intofront ends of each of the first GIs, and a cyclic postfix (CP) having asize corresponding to the remainder remaining after dividing the extraregion of the payload by the number of OFDM symbols is inserted into arear end of a final OFDM symbol configuring the payload.

In the signal-processing, the payload may be signal-processed based oninformation on whether the extra region of the payload is distributedand a disposition reference of the extra region, included in thebootstrap and the preamble.

In the signal-processing, channel estimation may be performed based onthe CP inserted into the rear end of the final OFDM symbol.

According to yet still another aspect of the present disclosure, atransmitting apparatus includes a processor configured to: generate aframe comprising orthogonal frequency-division multiplexing (OFDM)symbol, the OFDM symbols comprising a payload; insert first guardintervals (GIs) into the frame; insert second GIs into the frame; andinsert a cyclic postfix (CP) into a rear end of a final OFDM symbolconfiguring the payload; and a transmitter configured to transmitinformation from the processor, wherein the first GIs are sizedaccording to a fast Fourier transform (FFT) size of the OFDM symbolsconfiguring the payload, the second GIs are sized according to aquotient obtained by dividing an extra region of the payload, the numberof OFDM symbols, and the size of the first GIs by the number of OFDMsymbols, and the CP is sized according to a remainder resulting from thedividing.

The OFDM symbols may have the same size.

The OFDM symbols may include a first OFDM symbol having a first size anda second OFDM symbol having a second size different from the first size.

As set forth above, according to various exemplary embodiments, theremaining region of the payload is efficiently used, thereby making itpossible to improve data processing efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a hierarchical structure of atransmitting system according to an exemplary embodiment.

FIG. 2 is a diagram illustrating a schematic configuration of thebroadcasting link layer 1400, according to an exemplary embodiment.

FIG. 3A is a diagram illustrating a schematic configuration of atransmitting system or a transmitting apparatus, according to anexemplary embodiment.

FIGS. 3B and 3C are diagrams illustrating a multiplexing method,according to exemplary embodiments.

FIG. 4 is a block diagram illustrating a detailed configuration of theinput formatting block illustrated in FIG. 3A.

FIGS. 5A and 5B are diagrams illustrating a detailed configuration ofthe baseband framing block.

FIG. 6 is a diagram illustrating a configuration of a frame, accordingto an exemplary embodiment.

FIG. 7 is a block diagram illustrating a configuration of a transmittingapparatus according to an exemplary embodiment.

FIG. 8 is a block diagram illustrating a detailed configuration of thewaveform generation block, according to an exemplary embodiment.

FIG. 9 is a diagram illustrating a process of inserting first GIs andsecond GIs into the frame, according to an exemplary embodiment.

FIG. 10 is a diagram illustrating configurations of the first GI, thesecond GI, and the CP in detail, according to an exemplary embodiment.

FIGS. 11 to 16 are diagrams illustrating various methods of distributingand inserting the calculated extra region, according to an exemplaryembodiment.

FIGS. 17 to 19 are diagrams illustrating information on whether theextra region of the payload is distributed and a disposition referenceof the extra region, according to an exemplary embodiment.

FIG. 20 is a block diagram illustrating a configuration of a receivingapparatus according to an exemplary embodiment.

FIG. 21 is a block diagram provided to explain in detail a signalprocessor according to an exemplary embodiment.

FIG. 22 is a block diagram of a receiving apparatus according to anexemplary embodiment.

FIG. 23 is a block diagram describing the demodulator of FIG. 27according to an exemplary embodiment.

FIG. 24 is a flowchart provided to briefly explain an operation of areceiving apparatus from a time point when a user selects a service to atime point when the selected service is played.

FIG. 25 is a flow chart illustrating a controlling method of atransmitting apparatus according to an exemplary embodiment.

FIG. 26 is a flow chart illustrating a controlling method of a receivingapparatus according to an exemplary embodiment.

DESCRIPTION

Hereinafter, various exemplary embodiments will be described in detailwith reference to the accompanying drawings. Further, in the followingdescription, a detailed explanation of known related functions orconfigurations may be omitted to avoid unnecessarily obscuring thesubject matter. In addition, terms to be described below may varyaccording to a user's and an operator's intentions, the convention, orthe like as terms defined by considering functions. Therefore, thedefinition should be made according to the contents throughout thisspecification.

An apparatus and a method proposed in the exemplary embodiments can be,of course, applied to various communication systems including mobilebroadcasting services including a digital multimedia broadcasting (DMB)service, digital video broadcasting handheld (DVB-H), an advancedtelevision systems committee mobile/handheld (ATSC-M/H) service, anInternet protocol television (IPTV), and the like, communication systemsincluding a moving picture experts group (MPEG) media transport (MMT)system, an evolved packet system (EPS), a long-terms evolution (LTE)mobile communication system, a long-term evolution-advanced (LTE-A)mobile communication system, a high speed downlink packet access (HDSPA)mobile communication system, a high speed uplink packet access (HSUPA)mobile communication system, a 3rd generation project partnership 2(3GPP2) high rate packet data (HRPD) mobile communication system, a3GPP2 wideband code division multiple access (WCDMA) mobilecommunication system, a 3GPP2 code division multiple access (CDMA)mobile communication system, an Institute of Electrical and ElectronicsEngineers (IEEE) 802.16m communication system, a mobile Internetprotocol (Mobile IP) system, and the like.

FIG. 1 is a diagram illustrating a hierarchical structure of atransmitting system according to an exemplary embodiment.

Referring to FIG. 1, a service includes media data 1000 and signaling1050 for transferring information required to acquire and consume themedia data at a receiver. The media data may be encapsulated in a formatsuitable for transmission prior to the transmission. An encapsulationmethod may follow a Media Processor (MPU) defined in ISO/IEC 23008-1MPEG Media Transport (MMT) or a DASH segment format defined in ISO/IEC23009-1 Dynamic Adaptive Streaming over HTTP (DASH). The media data 1000and the signaling 1050 are packetized according to an application layerprotocol.

FIG. 1 illustrates a case in which an MMT protocol (MMTP) 1110 definedin the MMT and a Real-Time Object Delivery over Unidirectional Transport(ROUTE) protocol 1120 are used as the application layer protocol. Inthis case, a method for notifying information about an applicationprotocol, in which a service is transmitted, by an independent methoddifferent from the application layer protocol is required for thereceiver to know by which application layer protocol the service istransmitted.

A service list table (SLT) 1150 illustrated in FIG. 1 represents orindicates a signaling method and packetizes information about theservice in a table for satisfying the aforementioned object. Detailedcontents of the SLT will be described below. The packetized media dataand the signaling including the SLT are transferred to a broadcastinglink layer 1400 through a user datagram protocol (UDP) 1200 and anInternet protocol (IP) 1300. An example of the broadcasting link layer1400 includes an ATSC 3.0 link-layer protocol (ALP) defined in the ATSC3.0 standard (hereafter, referred to as ‘ATSC 3.0’). The ALP protocolgenerates an ALP packet by using an IP packet as an input, and transfersthe ALP packet to a broadcasting physical layer 1500.

However, according to FIG. 2 to be described below, it is noted that thebroadcasting link layer 1400 does not use only the IP packet 1300including the media data and/or the signaling as the input, and instead,may use an MPEG2-TS packet or general formatted packetized data as theinput. In this case, signaling information required to control thebroadcasting link layer is also transferred to the broadcasting physicallayer 1500 in the form of the ALP packet.

The broadcasting physical layer 1500 generates a physical layer frame bysignal-processing the ALP packet as the input, converts the physicallayer frame into a radio signal, and transmits the radio signal. In thiscase, the broadcasting physical layer 1500 has at least one signalprocessing path. An example of the signal processing path may include aphysical layer pipe (PLP) of ATSC 3.0 or the Digital VideoBroadcasting-Second Generation Terrestrial (DVB-T2) standard, and one ormore services or some of the services may be mapped to the PLP.

FIG. 2 is a diagram illustrating a schematic configuration of thebroadcasting link layer 1400, according to an exemplary embodiment.

Referring to FIG. 2, the input of the broadcasting link layer 1400includes the IP packet 1300, and may further include link layersignaling 1310, an MPEG2-TS packet 1320, and other packetized data 1330.

Input data may be subjected to additional signal processing based on thetype of the input data before ALP packetization 1450. As an example ofthe additional signal processing, the IP packet 1300 may be subjected toan IP header compression process 1410 and the MPEG2-TS packet may besubjected to an overhead reduction process 1420. During the ALPpacketization, input packets may be subjected to dividing and mergingprocesses.

FIG. 3A is a diagram illustrating a schematic configuration of atransmitting system or a transmitting apparatus, according to anexemplary embodiment. According to FIG. 3A, a transmitting system 10000according to the exemplary embodiment may include input formattingblocks 11000 and 11000-1, bit interleaved and coded modulation (BICM)blocks 12000 and 12000-1, framing/interleaving blocks 13000 and 13000-1,and waveform generation blocks 14000 and 14000-1.

The input formatting blocks 11000 and 11000-1 generate a baseband packetfrom an input stream of data to be serviced. Herein, the input streammay be a transport stream (TS), Internet packets (IP) (e.g., IPv4 andIPv6), an MPEG media transport (MMT), a generic stream (GS), genericstream encapsulation (GSE), and the like. For example, an ATSC 3.0link-layer protocol (ALP) packet may be generated based on the inputstream, and the baseband packet may be generated based on the generatedALP packet.

The bit interleaved and coded modulation (BICM) blocks 12000 and 12000-1determine an forward error correction (FEC) coding rate and aconstellation order according to an area (fixed PHY frame or mobile PHYframe) to which the data to be serviced will be transmitted, and performencoding and time interleaving. Signaling information about the data tobe serviced may be encoded through a separate BICM encoder according touser implementation or encoded by sharing a BICM encoder with the datato be serviced.

The framing/interleaving blocks 13000 and 13000-1 combine thetime-interleaved data with a signaling signal including the signalinginformation from a signaling block 15000 to generate a transmissionframe.

The waveform generation blocks 14000 and 14000-1 generate an orthogonalfrequency-division multiplexing (OFDM) signal in a time domain for thegenerated transmission frame, modulate the generated OFDM signal into anRF signal, and transmit the RF signal to a receiver.

The transmitting system 10000 according to the exemplary embodimentillustrated in FIG. 3A includes normative blocks marked with a solidline and informative blocks marked with dotted lines. Herein, the blocksmarked with the solid line are normal blocks, and the blocks marked withthe dotted lines are blocks which may be used when informativemultiple-input multiple-output (MIMO) is implemented.

FIGS. 3B and 3C are diagrams illustrating a multiplexing method,according to exemplary embodiments.

FIG. 3B illustrates a block diagram for implementing time divisionmultiplexing (TDM), according to an exemplary embodiment.

A TDM system architecture includes four main blocks (alternatively,parts) of the input formatting block 11000, the BICM block 12000, theframing/interleaving block 13000, and the waveform generation block14000. This TDM system architechure also includes a signalling block15000.

Data is input and formatted in the input formatting block 11000 andforward error correction is applied the data in the BICM block 12000.Next, the data is mapped to a constellation. Subsequently, the data istime and frequency-interleaved in the framing/interleaving block 13000and a frame is generated. Thereafter, an output waveform is generated inthe waveform generation block 14000.

FIG. 3C illustrates a block diagram for implementing layered divisionmultiplexing (LDM), according to an exemplary embodiment.

An LDM system architecture includes several other blocks as comparedwith the TDM system architecture. In detail, two separated inputformatting blocks 11000 and 11000-1 and the BCIM blocks 12000 and12000-1 for one of respective layers of the LDM are included in the LDMsystem architecture. The blocks are combined in an LDM injection blockbefore the framing/interleaving block 13000. And, the waveformgeneration block 14000 and the signalling block are similar to the TDMsystem.

FIG. 4 is a block diagram illustrating a detailed configuration of theinput formatting block illustrated in FIG. 3A, according to an exemplaryembodiment.

As illustrated in FIG. 4, the input formatting block 11000 includesthree blocks that control packets distributed to PLPs. In detail, theinput formatting block 11000 includes an encapsulation and compressionblock 11100, a baseband formatting block (alternatively, basebandframing block) 11300, and a scheduler block 11200.

An input stream input to the encapsulation and compression block 11100may be various types. For example, the input stream may be a transportstream (TS), an Internet packets (IP) (e.g., IPv4 and IPv6), an MPEGmedia transport (MMT), a generic stream (GS), a generic streamencapsulation (GSE), and the like.

Packets output from the encapsulation and compression block 11100 becomeALP packets (generic packets) (also referred to as L2 packets). Herein,a format of an ALP packet may be one of the Type Length Value (TLV), theGSE, and the ALP.

The length of each ALP packet is variable. The length of the ALP packetmay be easily extracted from the ALP packet itself without additionalinformation. The maximum length of the ALP packet is 64 kB. The maximumlength of a header of the ALP packet is 4 bytes. The ALP packet has alength of integer bytes.

The scheduler block 11200 receives an input stream including theencapsulated ALP packets to form physical layer pipes (PLPs) in abaseband packet form. In the TDM system, only one PLP called a singlePLP (S-PLP) or multiple PLPs (M-PLP) may be used. One service may notuse four or more PLPs. In the LDM system constituted by two layers, onein each layer, that is, two PLPs are used.

The scheduler block 11200 receives the encapsulated ALP packets todesignate how the encapsulated ALP packets are allocated to physicallayer resources. In detail, the scheduler block 11200 designates how thebaseband formatting block 1130 outputs a baseband packet.

A function of the scheduler block 11200 is defined by a data size and atime. A physical layer may transmit some of data in the distributedtime. The scheduler block 11200 generates a solution which is suitablein terms of a configuration of a physical layer parameter by usinginputs and information such as constraints and configuration from anencapsulated data packet, the quality of service metadata for theencapsulated data packet, a system buffer model, and system management.The solution is targets of a configuration and a control parameter whichare usable and an aggregate spectrum.

An operation of the scheduler block 11200 is constrained to a set ofdynamic, quasi-static, and static components. Definition of theconstraint may vary according to user implementation.

Further, a maximum of four PLPs may be used with respect to eachservice. A plurality of services which include a plurality of types ofinterleaving blocks may be implemented by up to a maximum of 64 PLPswith respect to a bandwidth of 6, 7, or 8 MHz.

The baseband formatting block 11300 includes baseband packetconstruction blocks 3100, 3100-1, . . . 3100-n, baseband packet headerconstruction blocks 3200, 3200-1, . . . , 3200-n, and baseband packetscrambling blocks 3300, 3300-1, . . . , 3300-n, as illustrated in FIG.5A. In an M-PLP operation, the baseband formatting block generates aplurality of PLPs as necessary.

The baseband packet construction blocks 3100, 3100-1, . . . , 3100-nconstruct baseband packets. Each baseband packet 3500 includes a header3500-1 and a payload 3500-2 as illustrated in FIG. 5B. A baseband packetis fixed to a length Kpayload. ALP packets 3610 to 3650 are sequentiallymapped to a baseband packet 3500. When the ALP packets 3610 to 3650 donot completely fit in the baseband packet 3500, these packets aredistributed between a current baseband packet and a next basebandpacket. The ALP packets are distributed in a unit of a byte.

The baseband packet header construction blocks 3200, 3200-1, . . . ,3200-n construct a header 3500-1. The header 3500-1 includes threeparts, that is, a base field (also referred to as, a base header) 3710,an optional field (also referred to as, an option header) 3720, and anextension field (also referred to as, an extension header) 3730, asillustrated in FIG. 5B. Herein, the base field 3710 is shown in everybaseband packet and the optional field 3720 and the extension field 3730may not be shown in every baseband packet.

A main function of the base field 3710 provides a pointer of an offsetvalue as bytes to indicate a start of a next ALP packet in a basebandpacket. When an ALP packet starts a baseband packet, the value of thepointer becomes 0. When there is no ALP packet that starts in thebaseband packet, the value of the pointer may be 8191 and a base headerof 2 bytes may be used.

The extension field 3730 may be used afterwards and for example, usedfor a baseband packet counter, baseband packet time stamping, additionalsignaling, and the like.

The baseband packet scrambling blocks 3300, 3300-1, . . . , 3000-nscramble the baseband packet.

FIG. 6 is a diagram illustrating a configuration of a frame, accordingto an exemplary embodiment.

Referring to FIG. 6, the frame 600 may be represented by a combinationof three basic components. In detail, the frame 600 may include abootstrap 610 positioned in a start portion of each frame, a preamble620 positioned behind the bootstrap 610, and a payload 630 positionedbehind the preamble 620.

Here, the preamble 620 includes L1 control signaling used to processdata included in the payload 630.

In addition, the payload 630 includes at least one subframe, and when aplurality of subframes are present in the payload 630, all of theplurality of subframes are disposed to be connected to each other basedon a time axis illustrated in FIG. 6.

Each subframe includes a fast Fourier transform (FFT) size, a GI length,a scattered pilot pattern, and the number of carriers (NoC), and the FFTsize, the GI length, the scattered pilot pattern, and the NoC are notchanged in the same subframe. However, the FFT sizes, the GI lengths,the scattered pilot patterns, and the NoCs may be different from eachother between different subframes in the frame 600.

Particularly, the bootstrap 610 may include a synchronization symbolpositioned in a start portion of each frame in order to detect a signal,precisely perform synchronization, estimate a frequency offset, andperform initial channel estimation.

In addition, the bootstrap 610 may include control signaling requiredfor receiving and decoding portions (the preamble 620 and the payload630) other than the bootstrap 610 in the frame 600.

In detail, the bootstrap 610 uses a fixed sampling rate of 6.144 Ms/secand a fixed bandwidth of 4.5 MHz, regardless of a channel bandwidth usedfor the portions other than the bootstrap 610.

FIG. 7 is a block diagram illustrating a configuration of a transmittingapparatus according to an exemplary embodiment.

According to FIG. 7, the transmitting apparatus 700 includes a framegenerator 710 and a GI inserter 720.

The frame generator 710 generates a frame including a plurality oforthogonal frequency-division multiplexing (OFDM) symbols. Here, theplurality of OFDM symbols are divided into a plurality of componentsincluding a bootstrap, a preamble, and a payload, which has beendescribed above in FIG. 6. Therefore, a detailed description will beomitted.

In addition, the GI inserter 720 inserts a guard interval (GI) into thegenerated frame. Here, the GI inserter 720 is included in the waveformgeneration block 14000 described in FIG. 3A. In detail, a processperformed in the waveform generation block 14000 will be described.

FIG. 8 is a block diagram illustrating a detailed configuration of thewaveform generation block, according to an exemplary embodiment.

Referring to FIG. 8, the waveform generation block 14000 includes apilot insertion 810, an MISO 820, an IFFT 830, a PAPR 840, a guardinterval insertion 850, and a bootstrap 860.

The pilot insertion 810 inserts at least one of a preamble pilot, ascattered pilot, a subframe boundary pilot, a continual pilot, and anedge pilot into the frame generated in the frame generator 710.

In addition, the MISO 820 applies a transmit diversity code filter tothe frame to perform MISO pre-distortion, and the IFFT 830 performsinverse-Fast Fourier transform (IFFT) on the frame to allow each OFDMsymbol to be divided into a useful region and a guard interval.

In addition, the PAPR 840 may perform correction of the OFDM signal,tone reservation, active constellation, and the like, in order todecrease a peak to average power ratio of the output OFDM signal.

Then, the guard interval insertion 850 may insert the guard intervalsinto the frame, and patterns of the guard intervals that may be inserteddepending on the FFT size of the OFDM symbol may be defined asrepresented by the following Table 1.

TABLE 1 GI Pattern Duration in Samples 8K FFT 16K FFT 32K FFT GI1_192192 ✓ ✓ ✓ GI2_384 384 ✓ ✓ ✓ GI3_512 512 ✓ ✓ ✓ GI4_768 768 ✓ ✓ ✓ GI5_10241024 ✓ ✓ ✓ GI6_1536 1536 ✓ ✓ ✓ GI7_2048 2048 ✓ ✓ ✓ GI8_2432 2432 ✓ ✓GI9_3072 3072 ✓ ✓ GI10_3648 3648 ✓ ✓ GI11_4096 4096 ✓ ✓ GI12_4864 4854 ✓

The above-mentioned guard interval insertion 850 may correspond to theGI inserter 720 according to an exemplary embodiment. In addition, aprocess of inserting first GIs having a size corresponding to the FFTsize of each of the OFDM symbols by a GI inserter 720 to be describedbelow may be performed based on the above Table 1.

The bootstrap 860 inserts the generated bootstrap into the frame.

Again, referring to FIG. 7, the GI inserter 720 inserts first GIs havinga size corresponding to a fast Fourier transform (FFT) size of each ofOFDM symbols configuring the payload into front ends of each of the OFDMsymbols, inserts second GIs having a size corresponding to a quotientobtained by dividing an extra region of the payload calculated based onthe FFT size of the OFDM symbols configuring the payload, the number ofOFDM symbols, and the size of the first GIs by the number of OFDMsymbols into front ends of each of the first GIs, and inserts a cyclicpostfix (CP) having a size corresponding to the remainder remainingafter dividing the extra region of the payload by the number of OFDMsymbols into a rear end of a final OFDM symbol configuring the payload.

In detail, the payload includes N OFDM symbols. Here, since a length ofthe frame is fixed and the FFT size of the OFDM symbol is also fixed,the payload may include a region remaining after it includes all of theN OFDM symbols. Here, the region remaining after the payload includesall of the N OFDM symbols is defined as an extra region.

In detail, the extra region may be calculated through the followingEquation 1 and Equation 2:

$\begin{matrix}{N_{extra} = {{\left( {T_{frame} - T_{Bootstrap}} \right) \times {BSR}} - {N_{symbols}^{preamble} \times \left( {N_{FFT}^{preamble} + N_{GI}^{preamble}} \right)} - {\sum\limits_{k = 1}^{N_{sub}}{N_{symbols}^{k} \times \left( {N_{FFT}^{k} + N_{GI}^{k}} \right)}}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$N _(symbols)=Σ_(k=1) ^(N) ^(sub) N _(symbols) ^(k)  [Equation 2]

Here, T_(bootstrap) means an entire time length of the bootstrapincluded in the frame. In addition, T_(frame) means an entire timelength of the frame. BSR means a baseband sampling rate for a regionexcept the bootstrap in the frame.

N_(symbols) ^(preamble) means the number of preamble symbols.

N_(FFT) ^(preamble) means an FFT size of a preamble symbol.

N_(GI) ^(preamble) means a guard interval length for the preamblesymbol.

Nsub means the number of subframes included in the frame.

N_(symbols) ^(k) means the number of OFDM symbols included in a k-thsubframe.

N_(FFT) ^(k) means an FFT size of the k-th subframe.

N_(GI) ^(k) means a guard interval length for the k-th subframe.

N_(extra) means the total number of extra samples included in the extraregion, and is defined to be the same as a size of the extra region inthe present disclosure.

Therefore, referring to the above Equation 1, it may be appreciated thatthe extra region according to an exemplary embodiment is calculated whena length corresponding to the bootstrap is subtracted from the entirelength of the frame, a length corresponding to the preamble symbol issubtracted in consideration of the FFT size and the GI of the preamblesymbol, and a length corresponding to all the subframes is subtracted inconsideration of the FFT size and the GI of each of the subframes.

In addition, the above Equation 2 means the total number of OFDM symbolsexcept the preamble in the frame.

FIG. 9 is a diagram illustrating a process of inserting first GIs andsecond GIs into the frame, according to an exemplary embodiment.

Referring to FIG. 9, the GI inserter 720 may insert first GIs 910 havinga size corresponding to an FFT size of each of OFDM symbols 940configuring the payload into front ends of each of the OFDM symbols.Here, the size of the first GI 910 may be determined depending on a sizeof the GI corresponding to the FFT size of each of the OFDM symbolsdefined in the above Table 1.

In addition, the GI inserter 720 may calculate the extra region of thepayload based on the FFT size of the OFDM symbols 940 configuring thepayload, the number of OFDM symbols 940, and the number of first GIs910. Here, the GI inserter 720 may calculate the extra region of thepayload through the above Equations 1 and 2, the FFT size of the OFDMsymbols 940 corresponds to N_(FFT) ^(k), the number of OFDM symbols 940corresponds to N_(symbols) ^(k), and the number of first GIs 940corresponds to N_(GI) ^(k).

In addition, the GI inserter 720 inserts second GIs 920 having a sizecorresponding to a quotient obtained by dividing the calculated extraregion by the number of OFDM symbols into front ends of each of thefirst GIs 910, and inserts a cyclic postfix (CP) 930 having a sizecorresponding to the remainder remaining after dividing the calculatedextra region by the number of OFDM symbols into a rear end of a finalOFDM symbol configuring the payload.

For example, when it is assumed that a size of the calculated extraregion is 11 and the number of OFDM symbols 940 configuring the payloadis 2, the GI inserter 720 may insert second GIs 920 having a sizecorresponding to a quotient obtained by dividing 11 by 2, that is, 5into front ends of each of the first GIs 910, and may insert a CP 930having a size corresponding to the remainder remaining after dividing 11by 2, that is, 1 to a rear end of a final OFDM symbol configuring thepayload.

The CP includes portions of the final OFDM symbol configuring thepayload. In addition, the first and second GIs may include portions ofeach of the OFDM symbols. It will be described in detail through FIG.10.

FIG. 10 is a diagram illustrating configurations of the first GI, thesecond GI, and the CP in detail, according to an exemplary embodiment.

Referring to FIG. 10, the CP 930 includes samples 940-2 from a startpoint of the final OFDM symbol to a point corresponding to a size of theremainder remaining after the calculated extra region is divided by thenumber of OFDM symbols, among a plurality of samples configuring thefinal OFDM symbol 940.

For example, when it is assumed that the calculated extra region is 11and the number of OFDM symbols is 2, the CP 930 includes samples from astart point of the final OFDM symbol to a point corresponding to a sizeof 1 remaining after 11 is divided by 2, among the plurality of samplesconfiguring the final OFDM symbol 940.

In addition, the first and second GIs are illustrated as a guardinterval (including extra samples) 950 in FIG. 10, and the guardinterval 950 illustrated in FIG. 10 includes the first and second GIs.The extra samples illustrated in FIG. 10 mean the second GIs.

Here, the first and second GIs, that is, the guard interval 950 includessamples 940-1 from a final point of the OFDM symbol 940 to a pointcorresponding to the sum of a size corresponding to the FFT size of theOFDM symbol 940 and a size of the quotient, among the plurality ofsamples configuring the OFDM symbol 940.

For example, when it is assumed that the calculated extra region is 11and the number of OFDM symbols is 2, the guard interval 950 includessamples from a final point of the OFDM symbol 940 to a pointcorresponding to the sum of a size (that is, a size of the first GI)corresponding to the FFT size of the OFDM symbol 940 and correspondingto 5, which is a quotient obtained by dividing 11 by 2, among theplurality of samples configuring the OFDM symbol 940.

The GI inserter 720 may insert the calculated extra region into theframe by various methods, which will be described.

FIGS. 11 to 16 are diagrams illustrating various methods of distributingand inserting the calculated extra region, according to an exemplaryembodiment.

[In the case in which OFDM symbols having the same FFT size are includedin the frame]

Referring to FIG. 11, all of a plurality of OFDM symbols 110 included inthe frame have the same FFT size, and first GIs 120 are inserted intofront ends of each of the OFDM symbols. Here, the first GI 120 isdenoted by GI.

In addition, the GI inserter 720 may calculate an extra region 130 basedon the above Equations 1 and 2 in consideration of an FFT size of theOFDM symbols 110, a length of the first GIs 120, and the number of OFDMsymbols 110.

In addition, the GI inserter 720 inserts second GIs 140 having a sizecorresponding to a quotient obtained by dividing the extra region 130 bythe number of OFDM symbols 110 in the calculated extra region 130 intofront ends of each of the first GIs 120, and inserts the remainderregion 150 remaining in the calculated extra region 130, that is, aregion 150 corresponding to a size corresponding to the remainderremaining after dividing the extra region 130 by the number of OFDMsymbols 110 into a rear end of a final OFDM symbol.

Here, the remainder region 150 inserted into the rear end of the finalOFDM symbol may be used to perform channel estimation of the followingframe.

In addition, the GI inserter 720 may also apply different dispositionreferences depending on a size of the remainder region 150 inserted intothe rear end of the final OFDM symbol.

In detail, when the size of the remainder region 150 is smaller than orequal to a preset reference, for example, ½ or ⅔ of the number of OFDMsymbols, the GI inserter 720 may insert the remainder region 150 intothe rear end of the final OFDM symbol, as illustrated in FIG. 11, andwhen the size of the remainder region 150 is equal to or larger than thepreset reference, for example, ½ or ⅔ of the number of OFDM symbols, theGI inserter 720 may sequentially insert regions having sizes obtained bydividing the remainder region 150 by the number of the plurality of OFDMsymbols with respect to the plurality of OFDM symbols included in thepayload.

Referring to FIG. 12, when the size of the remainder region 150 is thepreset reference, for example, ½ or ⅔ of the number of OFDM symbols, theGI inserter 720 may insert the remainder region 150 into front ends ofthe second GIs 140 inserted into front ends of each of the plurality ofOFDM symbols included in the payload.

For example, when the number of the plurality of OFDM symbols includedin the payload is 2, the GI inserter 720 may insert halves of theremaining region divided by the total number of symbols into the frontends of the second GIs 140 inserted into the front ends of the pluralityof OFDM symbols.

In addition, referring to FIG. 13, the remainder region 150 insertedinto the rear end of the final OFDM symbol described in FIG. 11 mayinclude information including a pilot pattern into which a pilot 150-1is inserted so that it may be used to perform channel estimation of thefollowing frame.

[In the case in which OFDM symbols having two or more FFT sizes areincluded in the frame]

In the case in which OFDM symbols having two or more FFT sizes arepresent in the frame, an example in which an extra region is insertedwill be described.

Referring to FIG. 14, one or more OFDM symbols 211 having a 32K FFT sizeand one or more OFDM symbols 221 having a 16K FFT size are included inone frame, first GIs 212 corresponding to the 32K FFT size are insertedinto front ends of each of the OFDM symbol 211 having the 32K FFT size,and first GIs 222 corresponding to the 16K FFT size are inserted intofront ends of each of the OFDM symbol 221 having the 16K FFT size. Inaddition, an extra region 230 is present.

Here, the GI inserter 720 does not insert regions having sizescorresponding to the quotient and the remainder obtained by dividing theextra region 230 by the number of the plurality of OFDM symbols into thefront ends of each of the OFDM symbols and the rear end of the finalOFDM symbol, respectively, as described in FIG. 11, but inserts theextra region 230 in a boundary portion between the OFDM symbol 211having the 32K FFT size and the OFDM symbol 221 having the 16K FFT sizeto allow the extra region 230 to function as a reference signal used forsynchronization and channel estimation.

In addition, even in the case in which the OFDM symbols having the twoor more FFT sizes are present in one frame, the GI inserter 720 may alsodivide and insert the extra region by the method as described in FIG.11.

Referring to FIG. 15, one or more OFDM symbols 211 having a 32K FFT sizeand one or more OFDM symbols 221 having a 16K FFT size are included inone frame, first GIs 212 corresponding to the 32K FFT size are insertedinto front ends of each of the OFDM symbol 211 having the 32K FFT size,and first GIs 222 corresponding to the 16K FFT size are inserted intofront ends of each of the OFDM symbol 221 having the 16K FFT size.

In addition, the GI inserter 720 may insert second GIs 230-1 having asize corresponding to a quotient obtained by dividing the extra region230 by the total number of OFDM symbols without considering the FFTsizes into front ends of each of the first GIs 212 and 222. In addition,the GI inserter 720 may insert a CP having a size corresponding to theremainder remaining after dividing the extra region 230 by the totalnumber of OFDM symbols without considering the FFT sizes into a rear endof the final OFDM symbol of the payload.

Alternatively, referring to FIG. 16, the GI inserter 720 may insert a CP240 having a size corresponding to the remainder remaining afterdividing the extra region 230 by the total number of OFDM symbolswithout considering the FFT sizes into the rear end of the final OFDMsymbol when the size of the CP 240 is a preset reference, for example, ½or ⅔ of the number of OFDM symbols, and sequentially insert regionshaving sizes obtained by dividing the extra region 230 by the number ofthe plurality of OFDM symbols with respect to the plurality of OFDMsymbols included in the payload when the size of the CP 240 is equal toor larger than the preset reference, for example, ½ or ⅔ of the numberof OFDM symbols.

In addition, the GI inserter 720 may also distribute and insert the CP240 having a size corresponding to the remainder in consideration of aratio between the FFT sizes of the OFDM symbols included in the frame inFIGS. 14 to 16.

For example, in the case in which the number of the plurality of OFDMsymbols included in the payload is 2, the GI inserter 720 does notinsert halves of the entire size of the remainder CP obtained bydividing the total number of symbols of the CP 240 having a sizecorresponding to the remainder by 2, which is the number of theplurality of OFDM symbols into front ends of the second GIs 230-1inserted into the front ends of each of the plurality of OFDM symbols,but may divide the entire size of the CP 240 having the sizecorresponding to the remainder in a ratio of 2:1 and insert regionshaving sizes divided in the ratio of 2:1 into the front ends of thesecond GIs 230-1 inserted into the front ends of each of the pluralityof OFDM symbols in the case in which the FFT sizes are 32K and 16K,respectively.

The GI inserter 720 may generate information on whether the extra regionof the payload is distributed and a disposition reference of the extraregion. In addition, the transmitting apparatus 700 according to anexemplary embodiment may further include a transmitter (not illustrated)transmitting the frame including the information on whether the extraregion of the payload is distributed and the disposition reference ofthe extra region. In detail, the transmitter (not illustrated) maytransmit the information on whether the extra region of the payload isdistributed and the disposition reference of the extra region as L1signaling.

FIGS. 17 to 19 are diagrams illustrating information on whether theextra region of the payload is distributed and a disposition referenceof the extra region, according to an exemplary embodiment.

Referring to FIG. 17, in the case in which an extra region 310 is evenlydistributed and inserted (320) into front ends of first GIs insertedinto front ends of each of the OFDM symbols (in the case in which theextra region is inserted by the same method as the method described inFIG. 11), the GI inserter 720 may generate information on whether theextra region 310 is distributed in a form of an ECP flag 330.

For example, the ECP flag 330 has a value of “0” in the case in whichthe extra region 310 is not distributed, and has a value of “1” in thecase in which the extra region 310 is distributed.

In addition, the GI inserter 720 may generate information 340 on adisposition reference of the extra region 310. The information 340 onthe disposition reference may include information on a method in whichthe extra region 310 is divided and disposed, and information on adisposition position of the extra region 310. For example, informationon whether the extra region 310 is evenly divided and is inserted intofront ends of each of the OFDM symbols or inserted into rear ends ofeach of the OFDM symbols, information on which the extra region 310 isdifferently divided depending on a ratio between the FFT sizes and isinserted into front ends of each of the OFDM symbols or inserted intorear ends of each of the OFDM symbols, information on which the extraregion 310 is inserted into a boundary region between the OFDM symbolshaving different FFT sizes, or the like, may be included in theinformation 340 on the disposition reference. In addition, theinformation on the preset reference described above (for example, theinformation on whether the remainder region 150 is smaller than andequal to or equal to and larger than ½ or ⅔ of the number of OFDMsymbols) may also be included in the information 340 on the dispositionreference.

In FIG. 17, the extra region 310 is evenly divided and inserted into thefront ends of each of the OFDM symbols, which corresponds to “Evenlydistribution(Forward)” 341. Therefore, the information 340 on thedisposition reference may store a value of “011”.

Referring to FIG. 18, the extra region 310 is inserted into a boundarybetween the OFDM symbol having the 32K FFT size and the OFDM symbolhaving the 16K FFT size without being distributed, which corresponds to“No Distribution(Center)” 351. Therefore, the information 350 on thedisposition reference may store a value of “001”.

In addition, referring to FIG. 19, the extra region 310 is evenlydivided and inserted into the front ends of each of the OFDM symbols,which corresponds to “Evenly Distribution(Forward)” 361. Therefore, theinformation 360 on the disposition reference may store a value of “010”.

In addition, the information 360 on the disposition reference mayinclude information 370 on a disposition ratio. In the case of FIG. 19,the extra region 310 is evenly divided and inserted into the front endsof each of the OFDM symbols, which corresponds to “Ratio(Equally)”.Therefore, the information 370 on the disposition ratio may store avalue of “001”.

FIG. 20 is a block diagram illustrating a configuration of a receivingapparatus according to an exemplary embodiment.

The receiving apparatus 2000 includes a receiver 2100, a bootstrapdetector 2200, and a signal processor 2300.

The receiving apparatus 2000 may be implemented to receive data from thetransmitting apparatus mapping and transmitting data included in aninput stream on at least one signal processing path.

The receiver 2100 receives a stream including the frame including thebootstrap, the preamble, and the payload. In detail, the receiver 2100may receive signaling information and the stream including the datamapped on at least one signal processing path. Here, the signalinginformation may include information about an input type of the inputstream input to the receiving apparatus and information about a datatype mapped on at least one signal processing path. Here, theinformation about the input type of the input stream may representwhether all of the signal processing paths in the frame are the sameinput type.

The signaling information may be a layer 1 (L1) signaling signaltransmitting an L1 signal for frame synchronization, and a preamble intowhich the L1 signaling information is inserted may include an L1 presignaling area and an L1 post signaling area. Further, the L1 postsignaling area includes a configurable field and a dynamic field.

The L1 pre signaling area may include information for analyzing the L1post signaling and information about the entire system, and the L1 presignaling area may be implemented to have the same length at all times.Further, the L1 post signaling area may include information about therespective PLP and information about the system, and in one superframe,the L1 signaling areas included in respective frames have the samelength, but contents included in the L1 signaling areas may vary.

In addition, the bootstrap detector 2200 detects the bootstrap in theframe. In detail, the bootstrap detector 2200 may detect the bootstrapbased on a correlation between an input signal and a pre-storedreference signal. In detail, the bootstrap detector 2200 may decidewhether the input signal and the pre-stored reference signal coincidewith each other to detect the correlation between the input signal andthe pre-stored reference signal. In addition, the bootstrap detector2200 may detect the bootstrap by measuring a start point of thebootstrap based on the detected correlation.

In addition, the signal processor 2300 signal-processes the preamblebased on the detected bootstrap, and signal-processes the payload basedon the signal-processed preamble.

Here, first GIs having a size corresponding to an FFT size of each ofOFDM symbols configuring the payload may be inserted into front ends ofeach of the OFDM symbols, second GIs having a size corresponding to aquotient obtained by dividing an extra region of the payload calculatedbased on the FFT size of the OFDM symbols configuring the payload, thenumber of OFDM symbols, and the size of the first GIs by the number ofOFDM symbols may be inserted into front ends of each of the first GIs,and a cyclic postfix (CP) having a size corresponding to the remainderremaining after dividing the extra region of the payload by the numberof OFDM symbols may be inserted into a rear end of a final OFDM symbolconfiguring the payload.

In addition, the signal processor 2300 may signal-process the payloadbased on information on whether the extra region of the payload isdistributed and a disposition reference of the extra region, included inthe bootstrap and the preamble. Here, the information whether the extraregion of the payload is distributed and the disposition reference ofthe extra region may be included as L1 signaling in the bootstrap andthe preamble.

In detail, the signal processor 2300 may effectively remove ISI based onthe first GIs and the second GIs inserted into each of the OFDM symbols.In addition, the signal processor 2300 may perform channel estimationbased on the remainder region remaining after distributing the extraregion disposed at the end of the frame.

In addition, in the case in which OFDM symbols having different FFTsizes are present in one frame, the signal processor 2300 performschannel estimation based on an extra region disposed in a boundarybetween the OFDM symbols having the different FFT sizes, thereby makingit possible to solve a channel estimation problem occurring when movingto regions having different FFT sizes.

FIG. 21 is a block diagram provided to explain in detail a signalprocessor according to an exemplary embodiment.

Referring to FIG. 21, the signal processor 2300 includes a demodulator2310, a decoder 2320 and a stream generator 2330.

The demodulator 2310 performs demodulation according to OFDM parametersfrom the received RF signals, performs sync-detection, and recognizeswhether a currently received frame includes necessary service data whenthe sync is detected from signaling information stored in a sync area.For example, the demodulator 2310 may recognize whether a mobile frameis received or a fixed frame is received.

In this case, if OFDM parameters are not previously determined regardinga signaling area and a data area, the demodulator 2310 may performdemodulation by obtaining OFDM parameters regarding the signaling areaand the data area stored in the sync area, and obtaining informationabout OFDM parameters regarding the signaling area and the data areawhich are disposed right after the sync area.

The decoder 2320 performs decoding of necessary data. In this case, thedecoder 2320 may perform decoding by obtaining parameters of an FECmethod and a modulating method regarding the data stored in each dataarea based on the signaling information. Further, the decoder 2320 maycalculate positions of necessary data based on the data informationincluded in a configurable field and a dynamic field. Thus, it maycalculate which positions of the frame a requested PLP is transmitted.

The stream generator 2330 may generate data to be served by processing abaseband packet input from the decoder 2320.

For example, the stream generator 2330 may generate an ALP packet fromthe baseband packet in which errors are corrected based on an ISSY mode,buffer size (BUFS), time to output (TTO) values and input stream clockreference (ISCR) values.

Specifically, the stream generator 2330 may include de-jitter buffers.The de-jitter buffers may regenerate correct timing to restore an outputstream based on the ISSY mode, BUFS, TTO values and ISCR values.Thereby, a delay for sync between a plurality of PLPs can becompensated.

The detailed components (the demodulator 2310, the decoder 2320, and thestream generator 2330) included in the signal processor 2300 describedabove may signal-process the preamble based on the detected bootstrap,and signal-process the payload based on the signal-processed preamble.

In addition, the detailed components (the demodulator 2310, the decoder2320, and the stream generator 2330) included in the signal processor2300 may effectively remove the ISI based on the first GIs and thesecond GIs inserted into the payload, and perform the channel estimationbased on the CP inserted into the rear end of the final OFDM symbol.

FIG. 22 is a block diagram of a receiving apparatus according to anexemplary embodiment.

Referring to FIG. 22, the receiving apparatus 4400 may include acontroller 4410, an RF receiver 4420, a demodulator 4430, and a serviceplayer 4440.

The controller 4410 determines an RF channel and a PLP in which aselected service is transmitted. At this process, the RF channel may bedefined by a center frequency and a bandwidth, and the PLP may bedefined by a PLP identifier (ID). Certain services may be transmittedthrough more than one PLP belonging to more than one RF channel percomponent constituting services. However, it is assumed in the followingdescriptions that all data required for playing one service aretransmitted through one PLP with one RF channel for convenientexplanation. Thus, services are provided with a unique data obtainingpath to play services, and the data obtaining path is specified by an RFchannel and a PLP.

The RF receiver 4420 extracts RF signals from a selected RF channel bythe controller 4410, and delivers OFDM symbols, extracted by performingsignal-processing of the RF signals, to the demodulator 4430. The signalprocessing may include synchronization, channel estimation andequalization. Information required for the signal processing ispredetermined between a transmitting apparatus and the receivingapparatuses or transmitted to the receiving apparatus in a predeterminedOFDM symbols among the OFDM symbols.

The demodulator 4430 extracts a user packet by performing signalprocessing of the OFDM symbols, and delivers to the service player 4440.The service player 4440 plays and outputs the service selected by a userwith the user packet. A format of the user packet may be differentaccording to implementing services. For example, a TS packet or an IPv4packet may be the user packet.

FIG. 23 is a block diagram describing the demodulator of FIG. 27according to an exemplary embodiment.

Referring to FIG. 23, the demodulator 4430 may include a frame demapper4431, a BICM decoder 4432 for L1 signaling, a controller 4433, a BICMdecoder 4434, and an output processor 4435.

The frame demapper 4431 selects OFDM cells constituting FEC blocksbelonging to a selected PLP from a frame constituted with OFDM symbolsbased on controlling information delivered from the controller 4433, anddelivers to the decoder 4434. Further, the frame demapper 4431 selectsOFDM cells corresponding to more than one FEC block included in the L1signaling, and delivers to BICM decoder 4432 for the L1 signaling.

The BICM decoder 4432 for the L1 signaling signal-processes the OFDMcells corresponding to the FEC blocks belonging to the L1 signaling,extracts L1 signaling bits, and delivers to the controller 4433. In thiscase, the signal processing may include extracting log-likelihood ratio(LLR) values for decoding low density parity check (LDPC) codes in OFDMcells, and decoding the LDPC codes by using the extracted LLR values.

The controller 4433 extracts an L1 signaling table from the L1 signalingbits, and controls operations of the frame demapper 4431, the BICMdecoder 4434, and the output processor 4435 by using values of the L1signaling table. FIG. 37 illustrates that the BICM decoder 4432 for theL1 signaling does not use controlling information of the controller 4433for convenient explanation. However, if the L1 signaling includes alayer structure similar to the L1 pre-signaling and the L1post-signaling described above, the BICM decoder 4432 for the L1signaling may be constituted with more than one BICM decoding block, andoperations of the BICM decoding blocks and the frame demapper 4431 maybe controlled based on upper-layer L1 signaling information, as clearlyunderstood in the above description.

The BICM decoder 4434 signal-processes the OFDM cells constituting FECblocks belonging to the selected PLP, extracts baseband packets, anddelivers the baseband packets to the output processor 4435. The signalprocessing may include extracting LLR values for coding and decodingLDPC codes in OFDM cells, and decoding the LDPC codes by using theextracted LLR values. These two operations may be performed based on thecontrolling information delivered from the controller 4433.

The output processor 4435 signal-processes the baseband packets,extracts a user packet, and delivers the extracted user packet to theservice player. In this case, the signal processing may be performed onthe controlling information delivered from the controller 4433.

According to an exemplary embodiment, the output processor 1235 mayinclude an ALP packet processor (not illustrated) which extracts an ALPpacket from a baseband packet.

FIG. 24 is a flowchart provided to briefly explain an operation of areceiving apparatus from a time point when a user selects a service to atime point when the selected service is played.

It is assumed that service information about all the services that canbe selected at an initial scan process of S4600 is obtained prior to aservice select process at S4610. The service information may includeinformation about an RF channel and a PLP which transmits data requiredfor playing a specific service in a current broadcasting system. Oneexample of the service information may be Program-SpecificInformation/Service Information (PSI/SI) of an MPEG-2 TS, which may beusually obtained through L2 signaling and an upper layer signaling.

When a user selects a service at S4610, the receiving apparatus modifiesa frequency transmitting the selected service at S4620, and performsextracting RF signals at S4630. While performing S4620 modifying thefrequency transmitting the selected service, the service information maybe used.

When the RF signals are extracted, the receiver performs S4640extracting L1 signaling from the extracted RF signals. The receivingapparatus selects the PLP transmitting the selected service by using theextracted L1 signaling at S4650, and extracts baseband packets from theselected PLP at S4660. At S4650 selecting the PLP transmitting theselected service, the service information may be used.

Further, S4660 extracting the baseband packets may include selectingOFDM cells belonging to the PLP by demapping a transmission frame,extracting LLR values for coding/decoding LDPC, and decoding LDPC codesby using the extracted LLR values.

The receiving apparatus performs S4670 extracting an ALP packet from theextracted baseband packet by using header information about theextracted baseband packet, and performs S4680 extracting a user packetfrom the extracted ALP packet by using header information about theextracted baseband packet. The extracted user packet is used in S4690playing the selected service. At S4670 extracting the ALP packet and atS4680 extracting the user packet, L1 signaling information obtained atS4640 extracting the L1 signaling may be used. In this case, a processof extracting the user packet from the ALP packet (restoring null TSpacket and inserting a TS sync byte) is the same as described above.According to the exemplary embodiments as described above, various typesof data may be mapped to a transmittable physical layer and dataprocessing efficiency may be improved.

FIG. 25 is a flow chart illustrating a controlling method of atransmitting apparatus according to an exemplary embodiment.

The controlling method of a transmitting apparatus illustrated in FIG.25 includes generating the frame including the plurality of OFDM symbols(S2510).

Then, the controlling method of a transmitting apparatus includesinserting the GIs into the generated frame (S2520).

Here, the plurality of OFDM symbols are divided into the bootstrap, thepreamble, and the payload, and in the inserting, the first GIs havingthe size corresponding to the FFT size of each of the OFDM symbolsconfiguring the payload may be inserted into the front ends of each ofthe OFDM symbols, the second GIs having the size corresponding to thequotient obtained by dividing the extra region of the payload calculatedbased on the FFT size of the OFDM symbols configuring the payload, thenumber of OFDM symbols, and the size of the first GIs by the number ofOFDM symbols may be inserted into the front ends of each of the firstGIs, and the cyclic postfix (CP) having the size corresponding to theremainder remaining after dividing the extra region of the payload bythe number of OFDM symbols may be inserted into the rear end of thefinal OFDM symbol configuring the payload.

Here, the CP may include portions of the final OFDM symbol configuringthe payload.

In addition, the first and second GIs may include portions of each ofthe OFDM symbols.

In addition, the CP may include samples from a start point of the finalOFDM symbol to a point corresponding to a size of the remainder, among aplurality of samples configuring the final OFDM symbol.

In addition, the first and second GIs may include samples from a finalpoint of the OFDM symbol to a point corresponding to the sum of a sizecorresponding to the FFT size of the OFDM symbol and a size of thequotient, among a plurality of samples configuring the OFDM symbol.

In addition, in the inserting, the information on whether the extraregion of the payload is distributed and the disposition reference ofthe extra region may be generated.

In addition, the controlling method of a transmitting apparatusaccording to an exemplary embodiment may further include transmittingthe frame including the generated information.

FIG. 26 is a flow chart illustrating a controlling method of a receivingapparatus according to an exemplary embodiment.

The controlling method of a receiving apparatus illustrated in FIG. 26includes receiving the stream including the frame including thebootstrap, the preamble, and the payload (S2610).

Then, the controlling method of a receiving apparatus includes detectingthe bootstrap in the frame (S2620).

Then, the controlling method of a receiving apparatus includessignal-processing the preamble based on the detected bootstrap, andsignal-processing the payload based on the signal-processed preamble(S2630).

Here, the first GIs having the size corresponding to the FFT size ofeach of the OFDM symbols configuring the payload are inserted into thefront ends of each of the OFDM symbols, the second GIs having the sizecorresponding to the quotient obtained by dividing the extra region ofthe payload calculated based on the FFT size of the OFDM symbolsconfiguring the payload, the number of OFDM symbols, and the size of thefirst GIs by the number of OFDM symbols are inserted into the front endsof each of the first GIs, and the cyclic postfix (CP) having the sizecorresponding to the remainder remaining after dividing the extra regionof the payload by the number of OFDM symbols is inserted into the rearend of the final OFDM symbol configuring the payload.

Here, in the signal-processing, the payload may be signal-processedbased on the information on whether the extra region of the payload isdistributed and the disposition reference of the extra region, includedin the bootstrap and the preamble.

In addition, in the signal-processing, the channel estimation may beperformed based on the CP inserted into the rear end of the final OFDMsymbol.

A non-transitory computer readable medium in which a programsequentially performing a signal processing method according to theabove exemplary embodiments is stored may be provided.

As an example, a non-transitory computer readable medium in which aprogram performing the generating of the frame including the pluralityof OFDM symbols and the inserting of the GIs into the generated frame isstored may be provided.

In addition, as an example, a non-transitory computer readable medium inwhich a program performing the receiving of the stream including theframe including the bootstrap, the preamble, and the payload, thedetecting of the bootstrap in the frame, and the signal-processing ofthe preamble based on the detected bootstrap and the signal-processingof the payload based on the signal-processed preamble is stored may beprovided.

The non-transitory computer readable medium is not a medium that storesdata therein for a while, such as a register, a cache, a memory, or thelike, but means a medium that semi-permanently stores data therein andis readable by a device. In detail, various applications or programsdescribed above may be stored and provided in the non-transitorycomputer readable medium such as a compact disk (CD), a digitalversatile disk (DVD), a hard disk, a Blu-ray disk, a universal serialbus (USB), a memory card, a read only memory (ROM), or the like.

At least one of the components, elements, modules or units representedby a block as illustrated in the drawings FIGS. 7, 8 and 20-23 may beembodied as various numbers of hardware, software and/or firmwarestructures that execute respective functions described above, accordingto an exemplary embodiment. For example, at least one of thesecomponents, elements, modules or units may use a direct circuitstructure, such as a memory, a processor, a logic circuit, a look-uptable, etc. that may execute the respective functions through controlsof one or more microprocessors or other control apparatuses. Also, atleast one of these components, elements, modules or units may bespecifically embodied by a module, a program, or a part of code, whichcontains one or more executable instructions for performing specifiedlogic functions, and executed by one or more microprocessors or othercontrol apparatuses. Also, at least one of these components, elements,modules or units may further include or implemented by a processor suchas a central processing unit (CPU) that performs the respectivefunctions, a microprocessor, or the like. Two or more of thesecomponents, elements, modules or units may be combined into one singlecomponent, element, module or unit which performs all operations orfunctions of the combined two or more components, elements, modules orunits. Also, at least part of functions of at least one of thesecomponents, elements, modules or units may be performed by another ofthese components, elements, modules or units. Further, although a bus isnot illustrated in the above block diagrams, communication between thecomponents, elements, modules or units may be performed through the bus.Functional aspects of the above exemplary embodiments may be implementedin algorithms that execute on one or more processors. Furthermore, thecomponents, elements, modules or units represented by a block orprocessing steps may employ any number of related art techniques forelectronics configuration, signal processing and/or control, dataprocessing and the like.

Although exemplary embodiments have been illustrated and describedhereinabove, the present disclosure is not limited to theabove-mentioned specific exemplary embodiments, but may be variouslymodified by those skilled in the art to which the present disclosurepertains without departing from the scope and spirit of the presentdisclosure as disclosed in the accompanying claims. These modificationsshould also be understood to fall within the scope of the presentdisclosure.

What is claimed is:
 1. A transmitting apparatus comprising: a framegenerator configured to generate a frame comprising a plurality oforthogonal frequency-division multiplexing (OFDM) symbols; and a guardinterval (GI) inserter configured to insert GIs into the generatedframe, wherein the plurality of OFDM symbols are divided into componentscomprising a bootstrap, a preamble, and a payload, and wherein the GIinserter inserts first GIs having a size corresponding to a fast Fouriertransform (FFT) size of each of the OFDM symbols of the payload into afront end of each of the OFDM symbols of the payload, inserts second GIshaving a size corresponding to a quotient into a front end of each ofthe first GIs, the quotient being obtained by dividing an extra part ofthe frame calculated based on the FFT size of each of the OFDM symbolsof the payload, the number of the OFDM symbols of the payload, and thesize of the first GIs by the number of the OFDM symbols of the payload,and inserts a cyclic postfix (CP) having a size corresponding to aremainder by dividing the extra part of the frame by the number of theOFDM symbols of the payload into a rear end of a final OFDM symbol amongthe OFDM symbols of the payload.
 2. The transmitting apparatus asclaimed in claim 1, wherein the CP comprises portions of the final OFDMsymbol of the payload.
 3. The transmitting apparatus as claimed in claim1, wherein the first GIs and the second GIs comprise portions of each ofthe OFDM symbols.
 4. The transmitting apparatus as claimed in claim 2,wherein the CP comprises samples, among a plurality of samples of thefinal OFDM symbol, from a start point of the final OFDM symbol to apoint corresponding to a size of the remainder.
 5. The transmittingapparatus as claimed in claim 3, wherein the first GIs and the secondGIs comprise samples, among a plurality of samples of the OFDM symbol,from a final point of the OFDM symbol to a point corresponding to thesum of a size corresponding to the FFT size of the OFDM symbol and asize of the quotient.
 6. The transmitting apparatus as claimed in claim1, wherein the GI inserter is further configured to generate informationon whether the extra part of the frame is distributed and information ona disposition reference of the extra part.
 7. The transmitting apparatusas claimed in claim 6, further comprising a transmitter configured totransmit the frame including the generated information.
 8. A receivingapparatus comprising: a receiver configured to receive a streamincluding a frame, the frame comprising components comprising abootstrap, a preamble, and a payload; a bootstrap detector configured todetect the bootstrap in the frame; and a signal processor configured tosignal-process the preamble based on the detected bootstrap andsignal-process the payload based on the signal-processed preamble,wherein first Guard Intervals (GIs) having a size corresponding to afast Fourier transform (FFT) size of each of orthogonalfrequency-division multiplexing (OFDM) symbols of the payload areinserted into a front end of each of the OFDM symbols of the payload,second GIs having a size corresponding to a quotient are inserted into afront end of each of the first GIs, the quotient being obtained bydividing an extra part of the frame calculated based on the FFT size ofthe OFDM symbols of the payload, the number of the OFDM symbols of thepayload, and the size of the first GIs by the number of the OFDM symbolsof the payload, and a cyclic postfix (CP) having a size corresponding toa remainder by dividing the extra part of the frame by the number of theOFDM symbols of the payload is inserted into a rear end of a final OFDMsymbol among the OFDM symbols of the payload.
 9. The receiving apparatusas claimed in claim 8, wherein the signal processor signal-processes thepayload based on information on whether the extra part of the frame isdistributed and information on a disposition reference of the extrapart, included in the bootstrap and the preamble.
 10. The receivingapparatus as claimed in claim 8, wherein the signal processor is furtherconfigured to perform channel estimation based on the CP inserted intothe rear end of the final OFDM symbol.
 11. A controlling method of atransmitting apparatus, the controlling method comprising: generating aframe comprising a plurality of orthogonal frequency-divisionmultiplexing (OFDM) symbols; and inserting guard intervals (GIs) intothe generated frame, wherein the plurality of OFDM symbols are dividedinto components comprising a bootstrap, a preamble, and a payload, andwherein in the inserting, first GIs having a size corresponding to afast Fourier transform (FFT) size of each of the OFDM symbolsconfiguring the payload are inserted into front ends of each of the OFDMsymbols, second GIs having a size corresponding to a quotient obtainedby dividing an extra region of the payload calculated based on the FFTsize of each of the OFDM symbols configuring the payload, the number ofthe OFDM symbols, and the size of the first GIs by the number of OFDMsymbols are inserted into front ends of each of the first GIs, and acyclic postfix (CP) having a size corresponding to a remainder remainingafter dividing the extra region of the payload by the number of OFDMsymbols is inserted into a rear end of a final OFDM symbol among theOFDM symbols configuring the payload.
 12. The controlling method of atransmitting apparatus as claimed in claim 11, wherein the CP comprisesportions of the final OFDM symbol configuring the payload.
 13. Thecontrolling method of a transmitting apparatus as claimed in claim 11,wherein the first GIs and the second GIs comprise portions of each ofthe OFDM symbols.
 14. The controlling method of a transmitting apparatusas claimed in claim 12, wherein the CP comprises samples, among aplurality of samples configuring the final OFDM symbol, from a startpoint of the final OFDM symbol to a point corresponding to a size of theremainder.
 15. The controlling method of a transmitting apparatus asclaimed in claim 13, wherein the first GIs and the second GIs comprisesamples, among a plurality of samples configuring the OFDM symbol, froma final point of the OFDM symbol to a point corresponding to the sum ofa size corresponding to the FFT size of the OFDM symbol and a size ofthe quotient.
 16. The controlling method of a transmitting apparatus asclaimed in claim 11, wherein the inserting comprises generatinginformation, the information comprising information on whether the extraregion of the payload is distributed and information on a dispositionreference of the extra region.
 17. The controlling method of atransmitting apparatus as claimed in claim 16, further comprisingtransmitting the frame including the generated information.
 18. Acontrolling method of a receiving apparatus, comprising: receiving astream including a frame including a bootstrap, a preamble, and apayload; detecting the bootstrap in the frame; and signal-processing thepreamble based on the detected bootstrap and signal-processing thepayload based on the signal-processed preamble, wherein first guardintervals (GIs) having a size corresponding to a fast Fourier transform(FFT) size of each of orthogonal frequency-division multiplexing (OFDM)symbols configuring the payload are inserted into front ends of each ofthe OFDM symbols, second GIs having a size corresponding to a quotientobtained by dividing an extra region of the payload calculated based onthe FFT size of the OFDM symbols configuring the payload, the number ofthe OFDM symbols, and the size of the first GIs by the number of OFDMsymbols are inserted into front ends of each of the first GIs, and acyclic postfix (CP) having a size corresponding to a remainder remainingafter dividing the extra region of the payload by the number of the OFDMsymbols is inserted into a rear end of a final OFDM symbol among theOFDM symbols configuring the payload.
 19. The controlling method of areceiving apparatus as claimed in claim 18, wherein in thesignal-processing, the payload is signal-processed based on informationincluded in the bootstrap and the preamble, the information includinginformation on whether the extra region of the payload is distributedand information on a disposition reference of the extra region.
 20. Thecontrolling method of a receiving apparatus as claimed in claim 18,wherein in the signal-processing, channel estimation is performed basedon the CP inserted into the rear end of the final OFDM symbol.